It is well known to utilize a sleeve valve as a kill valve for initially closing a port in the valve. In the event that it is desired to pump kill fluid into the annulus of a well a ball is dropped down the well conduit to engage a seat in the sleeve and shift the sleeve to an open position. Thereafter fluid flow can be pumped through the port and into the annulus to kill the well and overcome a dangerous situation in the well. However, the actuation of the sleeve valve requires a time delay to insert an actuating ball at the well surface and drop it through the fluid in the conduit and down to the location of the seat on the sleeve. Furthermore, in some installations the well conduit may include various other equipment such as a depth indicator, which, while allowing fluid flow therethrough, will not allow the passage of a ball for actuating a sleeve valve.
Therefore, the present invention is directed to a circulating kill valve which allows the valve to open quickly and communicate fluid from the bore of a well conduit to the outside of the conduit for supplying the necessary volume of kill fluid. The present invention provides a circulating kill valve which is opened in response to an increase in fluid flow rate and therefore provides a kill valve which can be opened without requiring a valve actuator to be dropped from the well surface down to the location of the kill valve.